[Lcd4linux-devel] Comments on "timer.c"

[Martin Z. <co...@mz...>]

Hi everybody!

On looking through "timer.c", I have found a few things that I want to
share with you.

1) Here's an excerpt of the manpage for "timercmp()":

   Some systems (but not Linux/glibc), have a broken timercmp()
   implementation, in which CMP of >=, <=, and == do not work; portable
   applications can instead use

     !timercmp(..., <)
     !timercmp(..., >)
     !timercmp(..., !=)

So I have changed the corresponding line in "timer.c" from

   if (timercmp(&Timers[i].when, &now, <=)) {

to

   if (!timercmp(&Timers[i].when, &now, >)) {

and committed this to SVN.

2) I find the function "timer_inc()" rather messy.  Why not change it to

   static void timer_inc(struct timeval *tv, const int msec)
   {
       struct timeval diff;
       diff.tv_sec = msec / 1000;
       diff.tv_usec = (msec % 1000) * 1000;

       timeradd(tv, &diff, tv);
   }

This is much less messy and works just as well.  I have not committed
this to SVN, as according to its manpage, "timeradd()" is

   Not in POSIX.1-2001.  Present on most BSD derivatives.

However, you already use "timercmp()", and the same restriction applies
here.  Thus, using "timeradd()" should be fine.  Shall I commit, or
shan't I commit?  That is the question... ;)

3) The variable "flag" in "timer_process()" is completely useless (it is
always "1" when tested).  This variable should either be removed for
clarity, or the code should be changed so it actually serves a purpose.

Best regards,

Martin
-- 
www.mzuther.de
www.radix-musik.de